Optical communications technology is finding increasing use in a variety of applications. For example, optical communications links are being considered for replacement of wire interconnections between integrated circuits on a circuit board, and between circuit boards within electronic systems.
One component in most optical communication links is a lens. For example, lenses are used to focus received light on a detector, collimate transmitted light into a beam, or to change the direction of a beam. One challenge in optical systems is when the focus of a lens or angle is to be changed. Lens with fixed optical properties in an optical system can be physically moved relative to each other to provide desired changes in focal length, for example, as in a zoom lens. Mechanical steering of beams using mirrors is known. Such systems can however be mechanically complex and difficult to integrate into an electronic system.
For example, in providing optical interconnection within an electronic system, tolerances in the card cage holding the circuit boards can result in varying positions of the circuit boards relative to each other. In addition to static changes in relative position present during initial placement of cards into the card cage, dynamic variations in relative position can be introduced during operation due to heating, vibration, and other environmental effects. These changes in relative position can result in loss of alignment and focus in an optical interconnect system. Providing mechanically adjustable lenses to compensate for these variations can be complex, expensive, and unreliable.